Spray tank for dispersing fluids from aircraft



Oct. 8, 1946;

R. GODDARD ETAL SPRAY TANK FOR DISPERSING FLUIDS FROM AIRCRAFT Filed April 24, 1942 4 Sheets-Sheet 1 lnv enf ors 311 175 51 Edda 5rd I Asmzngfil WEEK/E Oct. 8, 1946. R. GODDARD ,ET AL 2,403,774

' SPRAY TANK FOR DISPERSING FLUIDS FROM AIRCRAFT Filed April 24, 1942 4 Sheets-Sheet 2 D I Q .DWe nlars I I. 7 4% WE'az/E r 5/ By Omww Attorney Oct 1945- r R. GODDARD EI'AL SPRAY TANK FOR DISPERSiNG FLUIDS FROM AIRCRAFT 4 sheets-511 a 3 Filed April 24, 1942 Affomey O 3, 1946. w v R. GODDARD EI'AL 2,408,774

' SPRAY TANK Fox DISPERSING FLUIDS FROM AIRCRAFT 4 Sheets-Sheet 4 Inventors, ELPEZ? gudc/ard l /Emrzzg- E V VEEL/Ef' Afforney installed on modern aircraft.

Patented Del. 8, 1946 UNITED STATES PATENT OFFICE SPRAY 'TANKFOR DISPERSING FLUIDS FROM AIRCRAFT "Rupert Goddard, Havre de Grace, andFleming .R. Weaver, Edgewood Arsenal, .Md.

Application April 24, 1942, Serial No. 440,388

4 Claims. (015244-134) (Granted under the act of Marchc3, 1883, ,as amended April 30, 1928; 370 0. G. 757) The invention described hereinmay be manufactured and used by or for the Government-for .ggovernmental purposes, without the paymentto use of -any royalty thereon.

This invention relatesingeneral to the dispersionof fluids. vMore particularly the invention is concerned with a .method .and apparatu for dispersin ..fluids .from .moving aircraft.

.At the present time, smoke-producing liquids or chemical agents are ejected under pressure from an airplane or other moving aircraft .so

.thatthe liquid or chemical agent leaves the plane at approximately the same velocity as the-plane passes through th air, but in a substantially opposite direction, the liquid fallingin the form of ;relatively stable .drops I and reacting with the constituents of the air :tozform .a smoke screen. A toxic :or vesicant fluid, such .t'hat popularly termed mustard gas. is generally used, and hence the method and apparatus now being used for dispersing irritant .and'vesicant materials, of

which mustard gas i typical, .are in general. of

sucha character that the .ejected substance .will not affect the pilotor personnel, .orlcontact with the plane.

The most efficient methods :and appar-ati that have been, and arenow being-used fordispersing .materials from moving aircraft, embody among other things, va tank or storage reservoir for the fluid to be dispersed, and which can .:be readily Preferably, :the storage-tank .is somounted that it may be instantly released from .the plane .in .the event-of a .forced landing or :other contingency rendering :the presence on the planeof'thighly reactive'substances hazardous to the personnel and to those in the vicinity of a crash.

The storage tank is-equipped with a discharge line that :is .so disposed, preferably as to direct the ejected fluid rearwardly with respect to the .airplane to prevent injury to the .personneLmontact of the .fluid with the plane, .and for other desirable results known to thoseskilled in:this:art.

:Previous to now, the liquid tobe dispersed has been freed toflowiout throughithe discharge line by gravity .feed, :or, alternatively, a pressure-producing medium is resorted to; the latter being either-in the form of compressed carbon dioxide o-rsome mechanical apparatus, for example, a

pump or air compressor incorporatedin the system for forcing the reservoir filling therefrom and through the discharge or outlet line. For best performance, whether gravity or pressure deed is resorted :to, .the systemic-r apparatus usually, additionally, embodies some form of vent mechanism. Especially ;in systems where :the

gravity feed method of ejection is employedmust a vent :be 'providedif the desirable rapid and uniform discharge of the liquid filling is to be obtained.

Such storage type spray apparatus have in common certain'objectionablefeatures, most notably of which are the .generally complicated mechanically operated valve discharge .and vent :mecha- .nisms. Consequently, much time, thought, and

effort have been expended in developing forspray apparatus of the type with which we are herein concerned, discharge and vent mechanisms which, respectively, will be materially less complicated and more dependable in operation thanare :such asare now used.

In the course of our pursuit toward-this :most desirable end, many :and varying kinds of means for facilitating the venting and release .of fluid from the storage reservoir were, with varying-degrees of success, tried and ultimately for one soldered coveringof the discharge line. If this covering was soldered just sufficiently to facilitate its easy removal, it appeared too frail :for safety.

Another experiment :was with a flexible capfor the disjcharge .line. This cap was to be :removed by the useof an electrically ignited pyrotechnic 'mixture but-also was :found tobe impracticable.

It appeared from tests made: that before sufficient heat could be applied to completely melt the fusibl alloy holding the cap in place, liquid escapedfromtherdischarge line and caused solidi- ,fication of the fusedalloy,.thereby preventing the freeing of the cap.

.Next resort washadto a frangibleplate closure. This form of closure was .held in abeyancebecau-se of the apprehension at the time ,of the danger of premature breakage where the closure was of glass and mustard gas was used as the'liquid to be dispersed, and the possibility of destruction of perimentation with this type of closure lead to r the discovery of means whereby a frangible or readily rupturable disc in association with simple and efficient mechanism for rupturing the same could, advantageously, be incorporated in and made part of the chemical spray system or apparatus to be used therewith for venting and discharge control purposes.

An object of this invention is, therefore, to improve generally upon known methods and apparati for dischargingfluidsfrom aircraft.

Another object of the invention is to materially simplify vent and discharge mechanisms as are now known and used in such methods and apparati.

More specifically, an object of the invention is to render practical the use of a frangible element in the discharge and/or vent line of a chemical spray tank.

Another specific object of the invention is the provision of an effective, and practical assembly embodying a frangible sealing element and rupturing mechanism therefor which can with equal efliciency be used in either or both the vent and the discharge line.

Still another object of the invention is to provide a vent through the medium of which the air entering the reservoir may be utilized to insure the desired rate of discharge of the reservoir filling, that is, the fluid to be dispersed.

Yet another object of the invention is the adaption thereof to moving and stationary op- --erations with equally advantageous results; and

also its adaptability to'any shape or size of reservoir tank, and particularly to a tank having a streamlined body or otherwise shaped or equipped as may be warranted or required'to insure correct rates of fluid discharge and air admission.

The invention together with the above enumerated and other objects as will presently appear,

-will be best understood and appreciated from a perusal of the following specification made in connection with the accompanying wherein: 1

Figure 1 is a fragmentary outline of an airplane showing our improved spray tank mounted thereon.

Figure 2 is an elevational view of the tank, with certain parts broken away and other parts shown in section, and illustrating one form of assembly of vent and discharge mechanisms in accordance with the invention.

Figure 3 is a view similar to'Figure 2 and showing an alternate assembly of vent and discharge mechanisms in accordance with the invention.

Figure 4 is an enlarged, fragmentary vertical section through the vent-equipped end of the tank, and illustrating a spring loaded vent valve assembly in accordance with this invention.

Figure 5 is a view similar to Figure 4, and illustrating a frangible vent valve assembly forming part of this invention. 4

Figure 6 is a fragmentary top plan of the tank at the vent-equipped'end thereof.

Figure '7 is a view similar to Figure 2 and illustrating still another form of vent and discharge assembly. I

Generally, the invention is concerned with apdrawings, Q

4 paratus and methods employed for dispersing chemical agents from moving aircraft. The invention contemplates the employment of such procedure in a manner such that the toxic or vesicant fluid, 'as for example, the typical fluid mustard gas may safely be employed without risk to the safety of the apparatus employed, or the pilot or personnel of the plane.

Primarily, the invention contemplates the provision of improved means for venting the reservoir tank of the apparatus, as well as improved means for controlling the discharge of the chemable and convenient bracket structure ical agent or fluid from the tank. The invention further contemplates the provision of a mechanism that can be used with equal faciilty and advantages either as the vent control or as the discharge control, optionally, and, consequently can be used in pairs, and of which pair one such mechanism may be used as the vent control and other such mechanism of the pair used as the discharge control.

Referring now more particularly to Figure 2 of the drawings, there is illustrated in this figure a form of apparatus for carrying the invention in a simple phase into effect.

In the figure, as well as in other figures of the drawings, Bindicates a tank adapted to act as a reservoirfor the particular fluid that is to be dispersed. In constructing the tank, steel or such alloys as Duraluminum may be used if the employed chemicals are non-corrosive, while if the chemicals employed are of a corrosive nature, the tank is preferably constructed of commercial material, as for example, the commercial metal known as Monel. Also, while the shape of the tank may vary as desire or-expediency may dictate, it is preferably streamlined and so proportioned as to reduce to the minimum the air resistance encountered in flight.

In practice, the tank 5 may be located on the plane wherever deemed most advantageous, but by way of illustration and not by limitation, the tank is shown as mounted on and as nearly tangential to the wing as practicable. Any suit- (not shown) may be resorted to for suspending the tank, and a streamlined fairing 6, as shown, is provided to shield thesupporting brackets and other external interfering members with the View to further reducing the wind resistance.

Prior art forms of reservoir tanks generally employ what is commonly known and referred to as an elbow type of discharge line, and as such type of discharge line is well known, detailed description thereof is unnecessary. The tank of this invention eliminates this type of elbow discharge line since it has formed integral with the walls thereof a tubular discharge neck I. Discharge neck 1 extends rearwardly from the bottom portion of tank 5 and has connected therewith through the medium of a nipple 8 a tubular discharge spout or nozzle 9.. By reason of this characteristic feature of the tank, there results, in effect, an in-line flow of the liquid from the tank during the period of discharge.

In accordance with this invention the reservoir tank is advantageously equipped with an internal vent tube [0. The tube It) is in the form of an elbow, and extends inwardly and upwardly from the front wall of the tank in registry with a vent opening provided, as shown, in the tank wall.

For conveniently fillingthe tank 5 the same is equipped, preferably in the top wall thereof, with a filling opening for which a closure plug H i's-provided': A 'ccess to this opening may easily behad' upon removal of the fairing fii F To enhance-theeflioiency of the-apparatus and as a pronounced safety feature, the'reis provided an anti-splash shield 1-2. The shield H is tubular inform and telescopes the upper or'inner end of the vent or air inlet-H1 being spacedcircumferen'tially from the tube: l0 for obvious reasons. Recourse to such a shield will prevent the liquid in the tank risingto a levelin'the region of-the vent tubeas would result in the coveringof this end of the tube [0- vvith the -liquid-contents of the tank, andpossiblythespilling over and escape of the-filling through thev'enttube. Thus the use-0f such asshi'eld' l 2 mustibe regarded highly as asafety factor. Y

The manner of mounting or suspending the shield l2 may be varied-,ofcourse, as circumstances-warrant or dicta-te; its simplicity of-structure and the location of theventor air intake Hl providing flexibility with respect tomode of installation. Thus incidental to the assembling of glass, or alternately, in the form of a plate-or disc moldedfrom some phenolic condensation product, suchas Bakelite or similar plastic readilymold'able-'to"shape. Glass is least preferred dueto-itstendency to crack or break as a result-"of shock 'or' from pressure resulting from the tightening up of the retaining memberor members -employed for securing it-in place;

{It may also" be found advantageous, especially so;in 'theca se= of glass; to=conStl1uct thesealing element oflaininated sh'eets rather than a single thick sheet, due to thefact that then" a-slieet of known breaking strength might be used, and as many'thicknesses' of such sheet-used together; as would be required to give the element aselected predetermined breaking strength.

-I n addition to the above observations regard ing the materiail ironiwhich the sealing element is 'to be fabr-icated, it may also be observed that sucl'i'm-aterial should be acid-proof or non-corrodible soas to withstand the "effects of such of the tank the shield l2-atone endmay bereadily weldedor otherwise made substantially integral with the inner side-of thetopwalliof the tankias shown in Figure 4. Alternately, and asbest shown in Figure 5, the shield I2 is intimately associated with a screw-cap or plug l3 removably seating within an internally threaded boss i4 provided on the'top wallof the tank.

The boss I4 is welded to or, otherwise permanently united-with the tank wall to rim an opening provided therein;- and through which the shield I2 is passed into the tank toiassume proper position with respect to the-"vent tube, as the capplu'g: I this threaded home;-

To facilitate placement; and removalthereo'i,

cap-plug I3 is providedwitlrdiametrically opposed pairs of closely spaced lugs IE to be engaged by a suitable tool in a manner'apparent to'effect a turning movement of the cap-plug, in thedesired' or necessary direction j V A suitable gasket l6 is-interpos'ed between the boss {E 4 and the projecting peripheral edge of the cap-plug l=3-0verlying-the boss asshown. v

Access to cap-plug I3 is'had in the same mannerasabove set out with reference to gaining access to the'aforementioned plug I l'.

When this tank is employed in accordance with the invention, air from the surrounding atmosphere-passes throughthe tube 10 intothe tank under positive pressure for' displacing the fluid discharging underpressurethrough the. outlet nozzle 9; Thus with this tank mechanical appliances; compressedcarbon' dioxide, and similar pressure-producing apparatus are advantageously eliminated. Also notwithstanding the desired elimination of suchpressure-producingmedia as just referred to, air-under positive pressure is, as above explained', admitted into thetank throughout the period of discharge, and hence recourse to gravity feed of the fluid to the discharge line isnotnecessary.- 1 'Ad'verting again to Figure 2; there are illustrated therein simple forms of vent and dischargecontrol mechanisms; Intheir broad aspects,- these forms of control mechanisms are substantially identical; each essentially embodying a frangible sealingelement and means for applying force to the sealing element tocompletely dissipate the-latter-for assuring free flow or pass'age through the respective control mechanis'm 7 Different: types offrangible-- or rupturable sealing lements may be employeds; For example, the

substances astitaniu-m tetrachloride commonly used as smoke agentse a I The: f orrn of vent control mechanism 'slrown in Figure 2' i's-detai ledto advantage in Figures; and to-this latter figure reference is:now made 'for a better understanding of the' assembly involved in this particular form of vent mechanism. I

Asshown in Figure 5, thereis-mounted cm the inner end of the vent tube: I 0" axcap assembly indicated generally by the referencenulner al I l; This cap assembly includes a tubular body number I'B- that at its' lowerend: i's torme'd with an internal groove into which is -snug-l'y fitted -the upper extremityof thevent tube Ht At its lower end,'the-cap body I8 is welded 'or otherwise made fast' to, the vent tube: as shown, thus completing an': air tight joint between th'es'ememl'mrs;

At its: upper end' cap body-'- 1 8 is diametrically enlarged, and this enlargement is characterized by being'formed with an annular internal groove l9'and external'isorew threads'as shown.- The groovely constitut'es-a seat for a' sealing element 2 0i embodying those" characteristics herein before detailed as most desirable f or 'the purpose" of this invention; and gaskets 21, 21 of non-corrod'ible and acid-proof material 1 between whi'ch the margi'nal edge of the sealing 'element-'isacc'om'- modated I I securing" ring or annulus ZZthreads home on the=enlargement of the c'ap' body f8, and embod'ies an. inwardly directedflange 23"that'has-pressureexerting contact wi'th the upper gasket 2'l 'to tightly c'l'amp the sealing element or closure 20 and: associated gaskets within the confines of groove or seat I 9 1 to thereby prevent leakage;

To facilitate placement and removal of the securing annulus 22the' same; similarly to plug 13, is equipped with pairs of tool-co-acting lugs Eor: ru'pturi'ng, or' as actually"contemplatedl completely -'blo'win'g out the frangible" sealing or closure element 20, resort may be had toany suitable" mechanically, electrically or otherwise readily: operated, andi preferably: remote controlledi'd'evice found suitable for the intended purpose;

By way of illustration, and not by way'of' restriction; a preferred comme'rcial type of detonator, Z5: is shown mounted within the tube In and insufiicient proximity to-tlie closure 20 that the latter-will" receive the full force of theexplosion anaconsequently be so shatte'redandrup 'tured or"cbmpletely fragmented as to offer 'no r'e- 7 sistance to the on-rush of air passing through the tube I and into the tank 5.

Any suitably supporting or clamping means 26 is employed to hold fast the detonator 25 or its equivalent in place. A control wire or the like extends from the detonator to adjacent the operator so that he may operate the detonator readily.

As before noted, and as illustrated in Figure2 of the drawings, substantially the same identical means is employed as the discharge control mechanism, In Figure 2 such means is phantomly illustrated, whereas in Figure 7 this particular discharge control mechanism is detailed. Thus in Figure7, 21 indicates the frangible or rupturable sealin element of the discharge control mechanism illustrated. The sealing or closure element 27 is securely held in place by having its marginal edge clamped between an annular fixed shoulder 28 formed internally, of the coupling nipple 8 and that end of the discharge nozzle that is threaded into the nipple as shown.

The sealing or closure element 21 is identical in practically every respect with the sealing or closure element 20, and like the latter has its marginal edge disposed between non-corrodible and acid-proofgaskets 29, 29 to assure a fluid and air tight joint at the location of the sealing element.

Like the element 29, sealing element 21 is subject to the shattering force and effect of a detonator 30. Detonator 30 is identical with detonator 25, and means 3|, similar to the securing and fastening means 35, utilized for securing detonator 30 in place. Preferably, detonator 30 is advantageouslypositioned within nozzle 9, and has a control wire or the like extending therefrom to adjacent the operator so that he may conveniently operate the detonators in desired sequence or simultaneously as might be found most desirable. V

In order to illustrate the manner in which the principles of the invention may be further applied, a slightly modified form of closure-shattering, closure blow-out, or force-applying device is shown in Figure 3. V

' In this Figure 3 the force-applyin or blow-out device for the shatterable closure 23 of the vent control mechanism is indicated generally by the numera1 32 while 33 indicates generally the forceapplying or blow-out device for the shatterable closure 21 of the discharge control mechanism.

Each of the devices 32, 33 is in the form of a solenoid that, in the case of the device 32 is secured in operative position relative to closure and within the vent tube I 0 by a suitable clip 34, and in the case of the device 33 is secured in operative position relative to closure 21 and within the nozzle 9 or where otherwise found most desirable by a similar clip 35.

Devices 32, 33 are equipped with control means extending therefrom to adjacent the operator in order that-he might, as in the case of detonators 25, 30, conveniently operate them in sequence or simultaneously as desired or expediency may dictate, and to the end that venting of the tank and release of the fluid to be dispersed may be accomplished with the most advantageous and effective results.

From the foregoing it will be apparent that insofar as the factors pertaining to vent and discharge control, all the desirable features noted in connection with Figure 2 are retained, while at the same time the need for replacing the shock-producing instrumentalities employed for shattering the frangible closures following the exhausting of the tank contents is eliminated. Obviously in the case of solenoids, they may be used repeatedly over a considerable period of time, and no replacement thereof is ordinarily required incidental to each operation of recharging the tank with the chemical agent, and as is required where detonators or similar self-destructive media are employed. V

In order to control venting of thetank, or the admission of air into the tank in response to the air speed of the plane, and at the same time assure admission of air under a positive pressure throughout the period of discharge, a type of spring loaded vent control valve shown in Figure 4 may be used with beneficial results.

The valve of Figure 4 as a whole is shown mounted at the inner end of vent tube l0 and comprises a disc 36 and a stem 31, the stem being axially movable within the said end of the vent tube and the disc normally seating on the extremity of the tube.

Valve stem 3! at one end is diametrically reduced to provide a thread pin and a shoulder 39. Disc 36 is removably secured on the stem, being clamped on the pin 38 between shoulder 39 and a nut 40 threaded on the pin as illustratedl To improve the seating action of disc 36 and to compensate for wear there is disposed at the seating side of the disc a somewhat resilient gasket 40 of substantially the same diameter as the valve disc. Gasket 40 is held flat against the disc by a washer plate 41 of slightly less diameter than the gasket and the disc and'is accommodated with the inner end of the vent tube. Washer plate 4| is interposed between the gasket 40 and shoulder 39 as shown.

Manifestly any suitable means may be employed for mountin the valve provided such means makes provision for constraining the seating and unseating action of the valve to an axial movement relative to the inner end of the vent tube. In the embodiment illustrated, such means comprises a spider 42 secured in a mannerfound to be most practical for the purpose within the inner end of vent tube l0 and a removable guide sleeve 43 threaded through the hub of the spider and through which the valve stem 3'l has a sliding fit.

The guide sleeve 43 preferably has at one end thereof an enlarged head as shown to seat against the spider hub and limit movement of the sleeve through the hub incidental to assembly thus facilitating proper adjustment of the sleeve.

The spring of this valve is indicated at 44, and is sleeved on the valve stem 31. One end of the spring impinges against a collar 46 on the inner end of the valve stem, pin 41 acting as a stop or abutment for the collar. The opposite end of the spring is suitably seated against the sleeve 43. As is obvious, spring 44 acts in opposition to air pressure developing in the vent tube for normally holding the valve in closed or seated condition.

It'is apparent that this spring-loadedvalve is utilized as the vent control for the tank in conjunction with eltherthe discharge control mechanism of Figure 2 or the discharge control mechanism of Figure 3, optionally. In either event, the operation is substantially as follows:

The spring 44 of the vent valve is normally of suificient tension to keep the disc 36 seated against the inner end, of the vent tube against the action of air pressure just below that of the amstxitheivalve rcli air-speed or :thecp anee isz-discharseandidi nersionofthe chemiealasent con n s :Qf tai k "drsisfdesirsd; It. may 53.6 .8.5.- sumed that this :eperating tor icriticalrair speed :01, the-p an is 309 1B. :.;Thusat any air speed. below this; icritical air speed the vent valve ,is closed, while at ,wthisicritical speed or-at a sp ed xces 201011121 3). :speed -thezsent valve i open, '1 admitting :an =;ingress :of iair -into the tank; 1-: :In. neratingtthe-aapparatus initialupressure is .built1up-intank, dybyjnoreasing the air speed flfi pla e above; the herein assumed critical sp ed-to an extent isufli'cient to "cause :suchxa pressure through the vent tube that impinging v '36 will result in a slight compnession of spring" and an opening of the valve to admit a stream of air into the tank. When as a result of this action an equalization of external and internal pressures is attained, the air speed is reduced until critical or operating speed is reached. When critical speed is reached, the operator then actuates the discharge control device of Figure 2 or Figure 3 as the case may be for shattering or-blowing out the seal or closure element 21, permitting the escape of the fluid from tank 5 through the discharge nozzle 9.

This discharge of fluid will naturally result in a reduction of internal pressure, but the external air pressure on valve disc '36 at the critical air speed of the plane will, as is apparent from the foregoing, maintain valve disc 36 for the period of discharge open. Consequently, air under positive pressure is admitted through the vent valve throughout this period of fluid discharge, or until such time as the air speed is reduced below critical or operation speed, and at which time the valve will then close.

By critical or operation speed of the aircraft, and as such terms have been herein employed, is meant the velocity of the moving plane with :an internal groove-ell in which :the inlet in the air which is the factor determining tl e opportune moment of release of the smoke-producing agent. In this connection, it might be observed that complete atomization of the liquid to be dispersed can be obtained if counter-longitudinal motion between the liquid and the air is permitted to prevail at the time of release of the liquid, whereas the liquid falls as if poured from an elevation at rest and travels to the ground in substantially stable drops if this counter-longitudinal motion of the air at the time of discharge is prevented. Such counterlongitudinal movement of the air is prevented by projecting the liquid from the moving aircraft with a velocity substantially equal and opposite to the velocity in the air of the moving aircraft. Complete atomization at'the instant of discharge makes possible the discharge of highly persistent materials in comparatively non-persistent form on the ground, whereas if the liquid'is permitted to fall to the ground in the form of stable drops, the resulting smoke curtain may be made to rest advantageously on the ground.

Obviously the spring loaded vent valve just considered may be used in lieu of the vent controls of Figures 2 and 3 Without sacrificing any advantage, while at the same time obviating the need of replacing the vent seal or closure following each liquid dispersing action.

A funnel for effectively directin the air stream into the vent tube I 0 may be made readily available. As best shown in Figure 4, where a funnel is used there is welded to the wall of tank 5 a mounting ring 48 and the inlet end of the 110 itub'e terminates within: the confines 0f the :ring. lAiglailld ri g :49 isifitted into :the mounting rin 48,-. and at its .inner end is preferably :formed extremity of the vent :tubeseats. At its .outer end the gland-ring has formed ;-integ rally therewith a .fla'nge 5;| between :which and the :ring .148 agasketrfiz is-disposed.

The funnel, indicated by numeral 53,*isithre'aded onto thesm'ountingrin'galiB, and whenthreaded .home .an internal shoulder :54 formed :inwardly ofqthe naredrend :of the funnel jams :against :the -flange lid of thegland fringed?) ito'urge :the latter inward .of the mounting :ring and :into tight fit.- tin'g engagement :With the inlet :enclof the vent 1111136.. a '1. y gItzis' obviously clear that the eonsideredznmnfil assembly can be used regardless of the specific form of vent control employed.

It will also be understood from the foregoing that the various forms of vent and discharge controls may be interchangeably used, and that many variations in selection and use of the several forms of controls illustrated and described herein may be made. Likewise it is to be understood that the invention comprehends many variations in the mode of operation. Consequently, the invention is not limited to that which has been detailed herein by way of example, but is to be considered as embracing all forms of apparatus and variants of method falling within the scope of the appended claims.

For example, to those skilled in the art it will be appreciated that the invention may be readily adapted to the elbow-type of discharge line referred to in the reference herein to prior art forms of tanks. Then, too, any one of the vent controls contemplated by the invention may be utilized on connection with, for example, a suitable intermittent valve in the discharge line so that intermittent discharge of the fluid may be had when found desirable, and as would be desired in the employment of the invention as a signaling system. g

It will also be observed that while the invention is particularly well adapted to military purposes, it may be used to advantage for agricultural protection.

Having so described the invention, what we claim is: i

1. A liquid spray device for airplanes comprising a jettisonable storage tank for the liquid to be dispersed and adapted to be mounted on the airplane, an internally positioned vent tube opening at one end thereof to the atmosphere through the wall of the tank whereby positive pressure is producedv for discharging the contents of the tank and at an opposite end opening into the tank, a discharge line extending from the tank, destructible closure elements for the vent tube and discharge line respectively, and detonating instrumentalities disposed in proximity to each of the respective closures for removing them, each of said instrumentalities having electrical control wires extending therefrom for operation by remote control.

2. A liquid'spray device for airplanes comprising a. jettisonable storage tank for the liquid to be dispersed and adapted to be mounted on the airplane, an internally positioned venttube opening at one end thereof to the atmosphere through the wall of the tank whereby a positive pressure contents of the tank and at an opposite end 11 opening into tank, a discharge line extending from the tank, a rupturable sealing element mounted at the inner end of the vent tube, a

' rupturable sealing element mounted inward of mosphere through the wall of the tank and at an opposite end into the tank, a rupturable sealing element mounted at the inner end of thevent tube, a discharge line extending from the tank, a

12 rupturable sealing element mounted inward of the discharge line, and solenoids for rupturing the respective sealing elements disposed within the vent tube and discharge line.

4. A storage tank for liquid spray purposes having vent control means including a vent tube opening to the atmosphere at one end and at an opposite end opening to the interior of the tank and extending upwardly therein, and a vertical tubular shield telescoping the second named end of the tube and circumferentially spaced from the tube, said tubular shield extending downwardly from a, top wall of the tank to prevent liquid in the tank from splashing into the vent tube.

RUPERT GODDARD. FLENIING R. WEAVER. 

